Apparatus and method to produce cylindrical articles

ABSTRACT

A method and apparatus of applying stocking sheaths to cylindrical articles involving passing the articles longitudinally through the interior of a cylindrical mandrel bearing on its outer surface a supply of continuous stocking material. As the articles emerge from the mandrel they pickup overhanging stocking material and draw it off the mandrel. The interconnecting stocking between successively emerging articles is severed by shearing means. Spacing sufficient to provide stocking portions overhang the ends of the articles is achieved by driving the articles emerging from the mandrel at a greater speed than they are driven through the mandrel. Filter elements are formed of hollow, fibrous cylinders covered with a cloth stocking by tucking the overhanging ends of the stocking into the hollow ends of the cylinders.

nited States Patent [1 1 lioeffler et al.

[54] APPARATUS AND METHOD TO PRODUCE CYLINDRICAL ARTICLES [75]Inventors: Romain Eugene Loeifler, Defiance; Vernon Charles Plotts,Waterville,

both of Ohio [73] Assignee: Johns-Manville Corporation, New

York, NY.

[22] Filed: Sept. 29, 1970 [21] Appl. No.: 76,552

[52] US. Cl. ..29/411, 29/33 K, 29/208 R,

29/234, 29/429, 53/13, 53/204 [51] Int. Cl. ..B23p 17/00 [58] Field ofSearch ..29/419, 428, 473.3,

29/474.2, 411, 417, 517, 234, 33 K, 429, 208 R; 93/35 MW, 77 CL, 94 M;264/258; 53/33-34, 13, 204, 36

2,874,459 2/1959 Haldeman ..29/517 2,988,812 6/1961 Ohlinger ..29/5172,394,895 2/1946 Burhans ..29/419 X 2,540,272 2/1951 Malmstrom ..29/419X 1,913,828 6/1933 Brennan 93/35 MW 2,716,259 8/1955 Mott 93/35 MW2,683,500 7/1954 Goodloe ..29/419 X 3,008,859 11/1961 Smack 156/189 X2,724,176 11/1955 White ..29/419 3,026,609 3/1962 Bryan ..29/4193,067,504 12/1962 Lubben ..29/419 3,562,895 2/1971 Neibergall ..29/4l9Primary Examiner-Charlie T. Moon AttorneyJohn A. McKinney and Robert M.Krone [57] ABSTRACT A method and apparatus of applying stocking sheathsto cylindrical articles involving passing the articles longitudinallythrough the interior of a cylindrical mandrel bearing on its outersurface a supply of continuous stocking material. As the articles emergefrom the mandrel they pickup overhanging stocking material and draw itoff the mandrel. The interconnecting stocking between successivelyemerging articles is severed by shearing means. Spacing sufficient toprovide stocking portions overhang the ends of the articles is achievedby driving the articles emerging from the mandrel at a greater speedthan they are driven through the mandrel. Filter elements are formed ofhollow, fibrous cylinders covered with a cloth stocking by tucking theoverhanging ends of the stocking into the hollow ends of the cylinders.

24 Claims, 13 Drawing Figures PATENIEDMAYZZ m5 3. 733.67?

SHEET 3 0F 4 INVENTORS ROMAIN E. LOEFFLER VERNON C. PLOT TS ATTORNEYSAPPARATUS AND METHOD TO PRODUCE CYLINDRICAL ARTICLES BACKGROUND OF THEINVENTION Prior to the development of the present machinery, filtertubes having stocking coverings were assembled one at a time by handoperation. In this hand operation, cut to size tubes were inserted oneat a time into one end of a mandrel. The mandrel was of a convenientlength to be used in a generally vertical orientation by an attendant,and stocking covering was forced over the length of the mandrels outsidesurface before any tubes were inserted in the end. Forcing the stockingover the mandrel stretched the stocking to a periphery greater than thatof the tube to enable the stocking to pass over the tube. Afterinsertion of a tube, the attendant worked the stocking along the mandrelover the end within which the tube was not quite fully inserted, overthe exposed portion of the tube, and pulled a sufficient amount ofstocking past the tube to overhang the previously exposed portion of thetube. The extended portion of the tube, now covered by the stocking, waspulled, stocking attached thereto, from the mandrel. This caused thestocking to completely enclose the tube as it followed the tube off themandrel. The tube was pulled sufficiently clear of the mandrel so thatwhen the trailing stocking was severed with a pair of scissors, therewas an overhang of stocking on this end of the tube, duplicating that onthe front end. The stocking which is also left overhanging the mandrelnow had to be forced back onto the mandrel before another tube could beinserted and the procedure repeated. The overhanging ends were thentucked into the ends of the tube and tube cores inserted into the ends,forcing the stocking ends against the inside of the tubes.

The present machinery eliminates all of the above hand operations exceptfor insertion of the stocking ends and initial insertion of the tubecores. The machinery then completes the insertion of the tube cores oncethey have been properly positioned for entry into the tubes. The machinefurther incorporates the use of long lengths of filter tube and stockingor stocking coils in place of the cut-to-size coverings and tubes.

SUMMARY The present apparatus and method relates to machinery forproducing covered cylindrical articles, of which one form would .betubes, and more particularly, to machinery for assembling stockingcovers on filter tubes with the ends of the covers tucked into the tubeand tube cores inserted in the ends of the tube, forcing the ends of thestocking against the inside wall of the tube to form a filter unit.Particular use of stocking coils is made in obtaining the final stockingcovers.

Machinery of this nature can consist of a powered saw with numerouscutting blades for severing filter tube stock to obtain sized tubes ofthe proper length. A transfer table having indexing means for stock andtubes plus a conveyor attached thereto is combined with the saw. Theconveyor is integral with a dust collector and means for directing aplurality of tubes, consisting of a friction roller drive for drivingtubes piece against piece along a guide track, toward means for applyinga continuous length of covering material such as stocking. Mandrels areused to apply the covering material to the outer periphery of the tubeswhich mandrels are alternately rotatable from a supply to operativeposition to receive and dispense stocking from the outer surface of themandrel. When tubes are pushed piece against piece through the inside ofa mandrel covered with stocking in the dispensing or operative position,the stocking is engaged by the tubes leaving the mandrel which pull thestocking along to thereby cover those tubes. A separating means adjacentthe exit of the mandrels, consisting of a pair of drive rollerscoordinated with the friction roller drive, is provided to separate thebutted filter tubes while within the stocking. A severing means, in theform of a flying shear, is located between the pair of rollers to severthe stocking intermediate of the separation between the tubes. Theseparating means are followed by a printer to mark each stocking coverand a lateral transfer platform having a limit switch and plunger inconjunction with an inclined plane for laterally transferring thestocking covered tube to a flight conveyor. The conveyor carries the covered tubes past an attendant who tucks the ends of the stocking coversinto the tube and partially inserts the tube cores in proper alignmentwithin the tube ends. A combination nozzle-ram machine completes themachinery and the assembly by final insertion of the cores with the ramsconverging on both sides thereof, as well as blowing out the inside ofthe tube with high velocity air to remove any loose residual materialcaused by the cores abrading the tubes upon insertion.

Clearly, the machinery could be more highly automated, or in the reversesense, the process of covering a plurality of articles could also bepracticed manually.

The machinery automates into one process line operations previouslyrequiring numerous manual operations to assemble filter units havingstocking covers and tube cores. Further, machinery has been developedwhich is useful for processing any cylindrical article which requirescovering with a stocking material, or sheathing which is flexible, suchas plastic and rubber sheeting. The machinery gives higher productiondue to the increased speed of operation, and the use of continuouslengths of stocking and filter tube stock increases process efficiencyresulting in a more economical filter unit. The continuous nature of themachinery operation also aids in achieving a higher production.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of theline machinery;

FIG. 2 is a plan view of the machinery illustrated in FIG. 1;

FIG. 3 is an end view of the saw, transfer table and conveyor takenalong line 3-3 of FIG. 1;

FIG. 4 is an elevational view of the saw, transfer table and conveyorillustrated in FIG. 3;

FIG. 5 is a fragmentary elevational view of the driven rollers, gearshift, flying shear, printer and conveyor;

FIG. 6 is an end view of the drive roller and conveyor illustrated inFIG. 5;

FIG. 7 is a sectional view of the separating rollers taken along line7-7 of FIG. 5;

FIG. 8 is a fragmentary elevational view of the stocking machine;

FIG. 9 is an end view of the stocking machine illustrated in FIG. 8;

FIG. 10 is a fragmentary elevational view of the lateral transfermechanism;

FIG. 11 is an end view of the lateral transfer mechanism illustrated inFIG. 10;

FIG. 12 is a fragmentary plan view of the flight conveyor, rams and airnozzles; and

FIG. 13 is an elevational view of the flight conveyor, rams, and airnozzles illustrated in FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 illustrate a lineof machinery for assembling filter tubes 22, stocking covers 24 and tubecores 26 into filter units 28. The work flow is from left to right withsuitable lengths of filter tube stock entering the far side of thecombination saw-transfer table 32 where the tube stock is cut intopieces of a predetermined size or filter tubes 22 which are deposited onthe belt conveyor 34. A hood 36 with a stack 38 attached to the top ofthe hood 36 covers the saw-transfer table. The stack 38 is connected toa collector system (not illustrated) which collects the residualmaterial resulting from the cutting operation of the saws. The beltconveyor 34 transfers the cut pieces of tube 22 to the drive roller 40which pushes tube 22 against tube into the stocking machine 42. Theexternal surface of the tubes 22 is cleaned of loose residual materialbefore entering the stocking machine 42 by a dust collector 44 undernegative pressure located in front of the stocking machine 42. The tubes22 enter the inside of the upper or operative mandrel 46 of the stockingmachine 42 which is covered with a stocking 48 overhanging the exit endof the mandrel 46. The tubes 22 exiting the mandrel 46 engage thestocking 48 and carry it along thereby pulling the stocking 48 off themandrel. The stocking 48 is placed on the mandrel 46 in the lower orinoperative position by power driven feeder rollers 50, supplied by astorage disc 52 containing the stocking coil 48. Two mandrels 46 areincorporated into the stocking machine 42 to allow one mandrel 46 toreceive stocking 48, while the other mandrel 46 is dispensing stocking.

Upon leaving the stocking machine 42, the stocking covered tubes 22 areengaged by the separating roller 54 which by its rotation imparts to thetube 22 and attached stocking 48 longitudinal displacement at a speedgreater than that imparted by the drive roller to the abutting tube 22.Thus, the tubes are separated upon leaving the stocking machine 42. Thetubes 22 are now only interconnected by the stocking 48. A flying shear56 is used to subsequently sever the stocking creating independent tube22 and stocking cover 24 assemblies. The shear 56 is located between theseparating roller 54 and a traction roller 58 located downstream of theseparating roller 54. The traction roller 58 maintains tension on thestocking 48 between the rollers 54 and 58 to assure a clean cut by theshear 56. The individual tube 22 and stocking cover 24 assemblies thenpass on to the printer 60 where identification is placed on the stockingcover 24 of each tube 22. A lateral transfer platform 62 then transfersthe assemblies to a slat type conveyor 64 having flights 66 attachedtransverse of the conveyor over its entire face for receiving oneassembly each. The flight conveyor 64 is indexed to pass two flights 66at a time past the transfer platform 62, and the flights are open endedto accommodate insertion of tube cores 26 into the assemblies. The tubecores 26 are inserted manually after the ends of the stocking covers 24are manually tucked into the ends of the tubes. This procedure isperformed while the assemblies are on the flight conveyor 64 between thetransfer platform 62 and the nozzle-ram machine 68. The tube 22 andstocking cover 24 assemblies, with the tube cores partially inserted andreasonably aligned, are advanced to the nozzle-ram machine 68 where therams 70 converge on the tube cores 26 to complete insertion of the cores26 into the tubes 22 to form a filter unit 28. The nozzle-ram machine 68is a tandem mechanism for handling two assemblies at a time with theresult that the machine 68 is actuated only once for every two indexesof the trough conveyor 64. The assembly process is completed by an airblast from the nozzles 72 to blow any loose residual material from theinside of the filter unit.

The preferred embodiment is a line for assembling a stretchable, elastictype woven or knitted stocking 48 over tubes 22 of resin reinforcedglass fibers with perforated metallic tube cores 26 for securing theends of the stocking 48 to the inside of the tubes 22, as well as addingsupport to the filter unit 28. The filter 28 is of an outside-in-nature,with respect to flow and, therefore, the tubes are grooved on the outersurface to expand surface area and extend the fouling life of thefilter. Clearly, other cylindrical articles and covers are processableby the line machinery.

Referring to FIGS. 1 through 13, the machinery line illustrated in FIGS.1 and 2 can be more clearly understood by considering it as a series ofcomponents. FIGS. 3 and 4 illustrate the saw-transfer table 32 with abelt conveyor 34 attached. The saw-transfer table 32 is supported by aframe 74 consisting of structural steel legs, cross ties, and braces.Single lengths of tube stock 30 are supplied to the upper end of theinclined table- 76 from a supply source not illustrated, such as anautomatic feeder, or manually by an attendant. The tube stock 30 isinduced by gravity to move down the table 76 until it engages a seriesof feeder indexing fingers 78. The fingers are mounted in four equallyspaced rows over the circumference of a rotatable rod 80 and extend overthe length of the table 76. As the rod 80 is rotated a quarterrevolution at a time, one length of tube stock 30 is fed to waitingcarrier hooks 82 mounted on a drum 84 which is rotatable and alsoextends over the length of the table 76. Three rows of hooks 82 areequally spaced over the circumference of the drum 84 and each row has asufficient number of hooks 82 to support the individual filter tubes 22into which the tube stock 30 is cut upon being passed by the hooks 82through the path of the saw blades 86. The saw blades are adjustable innumber and position along the length of the drive shaft 88 which extendsover the length of the table 76 to enable various sizes of filter tubepieces 22 to be cut by the saw blades 86. Upon being cut, the filtertubes are deposited on the table 76 where again gravity induces thetubes 22 to roll downward until engaged by the discharge indexer 90,which duplicates the construction of the assembly described above forthe feeder indexing fingers 78. The drive shaft 88 for the saw blades 86is power driven by an electric motor 92 and belt drive 94. The drum 84,discharge indexer 90, and feeder indexing fingers 78 assembly aremechanically linked to index in unison upon a single from a photocell 96sighting across the belt conveyor 34. When the last tube 22 istransferred by the conveyor 34 past the table 76, the photocell 96signal actuates the linkage resulting in a group of tubes 22 beingdischarged onto the conveyor 34 while another length of tube stock 30 isfed to the saw blades 86. The

discharge onto the conveyor 34 is accomplished by a quarter revolutionof the discharge indexer 90.

A guard 98 enclosing the bottom and sides of the top of the conveyorbelt 100 maintains reasonable alignment of the tubes 22 on the top ofthe belt 100. The belt 100 is supported by an idler drum 102 and drivedrum 104 with the drive drum driven by a chain and sprocket loop (notillustrated) interconnected to the main line drive 106 illustrated inFIG. 5. The conveyor 34 deposits the tubes 22 onto a guide track 108which directs them to the drive roller 40 illustrated in FIG. 5. Theconveyoris interconnected to the line drive 106 to assuresynchronization of the conveyor 34 belt speed with that of the driveroller 40, thereby giving a smooth transition of tubes 22 from conveyor34 to drive roller 40.

FIGS. 5, 6 and 7 illustrate, in addition to the drive roller 40, theseparating and traction rollers 54 and 58, plus the interconnectingdrive components. The components which make the rollers 40, 54 and 58 anintegral drive are the chain and sprockets which make up the drive loop110 and interconnecting loops 112 and 114. Loop 112 interconnects thedrive loop 110 and drive roller 40. Loop 114 interconnects drive loop110 and the separating traction rollers 54 and 58. In addition, a gearshift 116 is provided consisting of the handle 118 on which is mountedan engaging gear 120. The handle 118 is swingably mounted and slidableparallel to the axis of rotation to engage selectively the face ofvarious diameter drive gears 122 which are driven by the drive loop 110.The gear shift allows the separating and traction rollers 54 and 58 tobe driven at a variety of speeds which are in excess of but correlatedto the speed of the drive roller 40. The rollers 40, 54 and 58 aremounted on the stub shafts 124, the other ends of which are attached tosprockets within the loops 110, 112 and 114 of the integral drive.Surfaces of the rollers 40, 54 and 58 are covered with a resilientmaterial of sufficient frictional characteristics to prevent slippagebetween rollers 40, 54 and 58, and tubes 22. Slippage between rollers40, 54 and 58 and tubes 22 is further avoided by pressure applied to thetubes 22 from the rollers 40, 54 and 58 when contact is made, andcontouring the face of the rollers 40, 54 and 58 to the cross section ofthe tubes.

FIGS. 8 and 9 illustrate the stocking machine 42 consisting of mount 126to which a cantilevered shaft 128 is journaled for rotation of the shaft128 about its longitudinal axis. Two mandrels 46 are connected to andsupported by the shaft 128 through a box member 130 symmetricallyattached to the shaft 128. The ends of the mandrels pass through the boxmember 130 to provide access to the inside of the mandrels 46, which arehollow. The mandrels 46 are rotatable about the shaft 128 to interchangethem between the upper or operative position, and lower or inoperativeposition. Also illustrated are a stocking coil 48 on a storage disc 52which has retaining and guide pins 134 and 136, respectively. Thestocking coil 48 is illustrated being fed onto the mandrel 46 in theinoperative position, while the other mandrel 46 is maintained in theoperative position having already received the proper amount of stocking48. The stocking 48 is fed onto the mandrel 46, after an initial manualstart, or set-up, by a pair of powered feeder rollers 50, whichfrictionally engage the stocking 48 and move the stocking 48 over thestationary mandrel 46 by rotation of the rollers 50. The

rollers 50 are attached to a movable support 138 and driven off of astiff chain drive 140 along which the drive sprocket 142 moves. Drivesprocket 142 connects the chain drive 140 to the chain loop 144 ofrollers S0. The support is manually movable in the longitudinaldirection of the mandrels 46 along a way 139. The way 139 allows thesupport 138 to be moved along the length of the mandrel and to bedisengaged from the mandrel by moving clear of the free end of themandrel when the mandrel is to be rotated. A clamp 146 is provided toengage the inoperative mandrel and thereby maintain the position of bothmandrels once they have been rotated into position. The stiff chaindrive 140 is powered by an independent motor-gear drive 148 through aninterconnecting shaft 150.

Alternative drives for the rollers such as belt and pulley andalternative techniques for interchanging mandrels such as lateraldisplacement on a pendulously supported mandrel are available. Therollers are illustrated as top or bottom engaging with contoured faces,but could also have other orientations such as being side mounted, andother configurations such as V grooved. Such variations are anticipatedand should not restrict the breadth of the present machinery line orprocess. In like sense, other ways of storing and and feeding stocking48 into the stocking machine 42, such as sliding clamps which engage thestocking 48 on the mandrel 46 and move the stocking forward where it isreleased and the clamps return to repeat the motion, are available andthe present apparatus should not be limited to the particular methodillustrated.

Returning to FIGS. 5, 6 and 7, it can be seen that the drive roller 40engages each tube 22 and pushes the tube against a preceding tube inendless progression into the inside of the mandrel 46 in the upper oroperative position and out the other side. As the tubes 22 leave themandrel 46, each in turn engages the stocking 48 which encompasses theend of the mandrel overhanging it in a restrictive manner caused by thediameter of the mandrel being large enough to stretch the stocking 48when placed over it. While the machine is particularly suitable forprocessing stockings 48 of an elastic nature by overcoming thedifficulty of stretching the stocking 48 over the tube when the relaxedperimeter of the stocking 48 is smaller than the outside perimeter ofthe tube 22, clearly, other stocking material could be used if flexibleenough to overhang the mandrel and any cylindrical article could becovered. The tubes then carry the stocking 48 along, pulling thestocking 48 off the mandrel 46. Tube 22 and stocking 48 are then engagedby the separating roller 54 which turns at a higher rate of speed thanthe drive roller 40, thereby advancing the tube 22 and stocking 48thereunder faster than the following line of butted tubes is advanced bythe drive roller 40. Thus, a separation of tubes results to allow theflying shear 56 to pass between the tubes and sever the stocking 48which interconnects the tubes. To maintain tension on the stocking 48during passage of the shear 56, a traction roller 58 is providedadjacent the separating roller 54 on the downstream side to firmlymaintain the position of the prior tube 22 and stocking 48 relative tothe tube 22 and stocking 48 beneath the separation roller 54. Once thestocking 48 is severed, an independent tube 22 and stocking cover 24assembly is created which passes on to the printer 60 for proper markingof the stocking cover 24.

The flying shear 56 consists of two double-edged knife blades 152capable of cutting on both the forward and return passes. The knifeblades 152 are attached to spur gears 158 which are pivotally mounted ona support shaft 154 supported by two support plates 156. A double rack160 actuated by a pneumatic cylinder 162 drives one of the spur gears158 directly and the other gear 158 through a gear train 159 in unisonwith the first gear 158 but in the counter direction. The blades are insliding contact and positioned to maintain their point of intersectionon a vertical line through the center of tube 22.

Again, other means of severing the stocking 48, such as a circularrotating blade, are available and, therefore, the means illustratedshould not be viewed in a restrictive sense of limiting the breadth ofthe machinery line.

The printer 60 consists simply of a marking wheel 164 whose peripheryengages both the stocking covers 24 leaving the traction roller 58 andthe inking wheel 166 whereby the raised, scribed surface on the markingwheel periphery receives ink which is deposited on the stocking 24covers upon rotation of the wheel. A drive wheel 168 is connected to themarking wheel 164 by a belt 169 and to the separation and tractionroller drive by chain and sprocket. Thus, the rollers 54 and 58 plusmarking wheel are driven with identical peripheral speed which in turnis identical to the speed of the tube 22 and stocking cover 24assemblies. The result is a contact between stocking covers and wheel164 and rollers 54 and 58 free of slippage. The printer 60 is supportedby a backing plate 170 attached to an intermediate frame 172 which is acontinuation of the sawtransfer table frame 74. Both frames 74 and 172are segments of the line base 174 by virtue of being structurally tiedtogether with the support frames of all the line components. Thus, theline of machinery has one common base 174 consisting of structural steellegs, cross ties and braces.

Up to this point in the assembly process, the tubes have travelledlongitudinally through the line machinery. Insertion of the tube coresinto the tube 22 and stocking cover 24 assemblies requires that there begreater access to the ends of the tubesthan the separation developed byroller 54. The trough conveyor 64 is introduced into the line at thispoint in an orientation transverse to the guide track 108 from which thework is to be deposited on the trough conveyor 64. To make this rightangle transfer a smooth one, a lateral transfer platform 62, asillustrated in FIGS. and 11, is incorporated into the line between guidetrack 108 and trough conveyor 64.

The transfer platform 62 provides a horizontal bed 176 for receiving thetube 22 and stocking cover 24 assemblies which are pushed piece againstpiece from the printer 60 along the guide track 108. FIG. 1 illustratesthe mating of guide track 108 and transfer platform 62 with the track108 positioned to smoothly deposit the tube 22 and cover on the bed 176.The bed 176 is supported by side plates 178 which are tied to thetransverse frame 180 which is also a segment of the line base 174. Theside plates are further tied across the front by a structural bar 182and an inclined surface plate 184. The inclined plate 184 terminates atits lower end at a point which closely coincides with the top edge ofone flight 186 of the flight conveyor 64. This inclined plate 184 guidesthe tube 22 and stocking cover 24 assemblies into the flights 186 as theflights 186 are indexed past. The tubes 22 and stocking covers 24 aremoved onto the inclined plate 184 from the bed 176 upon contacting thelimit switch 188. The switch 188 activates a plunger 190 which in turnpushes the tube 22 and stocking cover 24 over the guide bar 192resulting in a gravity induced fall down the inclined plate 184.

A shaft 194 is journalled to flange bearings 196 on the inside faces ofthe side plates 178. This shaft 194 supports the conveyor drive sprocket198 for the conveyor chain 200 as well as a driven sprocket 202connected by a chain loop 204 to a motor-reducer drive 206. The chain200 carries the flights 186 having generally U shapes with the legspointing upward and flared outward and with the bottom attached toindivid ual lengths of the chain 200. Both chain 200 and flight "186 arecontinuous to form the flight conveyor 64 when looped over the idlersprocket 208 (See FIG. 12).

The flight conveyor passes the nozzle-ram machine 68 in order to reachthe idler sprocket 208. The nozzleram machine 68 is supported by thetransverse frame 180 and terminates the line. As the tube 22 andstocking cover 24 assemblies approach the nozzle-ram machine 68, theends of the stocking cover 24 are tucked into the tube 22 and tube cores26 are positioned and aligned in the tube 22 over each of the ends ofthe stocking covers 24. Both of these operations are manual. With everytwo indexes of the trough conveyor, the rams converge uniformly upon thetube cores 26 extending from the two tubes 22 within the confines of therams 70, thereby inserting the tube cores 26 into the tubes 22 to form afilter unit 28. The pairs of nozzles 72 on each side of the troughconveyor operate in conjunction with the rams 70 to blow a high velocitystream of air through the inside of the filter units 28, afterconverging upon the units 28, to clean out any loose residual material.The pair of nozzles 72 which have the springs 214 mounted behind theirface flanges 216 are movable along the axis of the nozzles 72. Thesenozzles are the air supply nozzles and are illustrated in the extendedposition maintained by the springs 214. The nozzles are forced againstthe springs 214 upon converging on the filter units and move into thenozzle body 218 to activate the flow of air. The result is that the airflow is only on when the face flanges 216 of the nozzles 72 arereasonably sealed against the filter units thereby conserving air atother times and directing it to the most efficient use. The indexing ofthe flight conveyor, advancing the tube 22 and stocking cover 24assemblies two positions, is controlled by a signal activated by aforward and return pass of the shear 56 between the rollers 54 and 58(see FIG. 5), and the converging of the nozzle-ram machine 42 iscontrolled by a signal generated by a cam on the shaft of idler sprocket208 and limit switch combination which also stops the conveyor. Thenozzle-ram machine 42 is retracted when the pressure therein builds upto within a 20 lb. differential of supply pressure.

The rams 70 consist of an angular plate attached to a common plate 220on which both rams 70 and nozzles 72 are mounted. The common plates 220are supported by the rail shafts 222 in a sliding manner by attachedbushings 224. The motive force for the rams 70 and nozzles 72 is a powercylinder 226, air operated, acting through a pair of guide racks 228 anda free wheeling pinion 232 to assure that convergence from both sidestoward the middle occurs. The nozzles 72 opposite the supply nozzles 72are actually receivers for residual material having a collection box 230attached to the back of both.

The present line machinery has now been described in its preferredembodiment, but should not be limited by this embodiment. Clearly, othermeans are available for cutting and conveying the tubes 22 to the driveroller 40, such as a shear, a trough and a pusher mechanism. A pushermechanism plus an extractor could replace the rollers 40, 54 and 58.Further, other conveying means such as indexing fingers or a walkingbeam between fixed rails could be employed in place of the flightconveyor 64 calling for modifications to the transfer platform 62 aswell.

Even more significant, while the preferred embodiment concerns itselfwith filter units 28, it is anticipated that the apparatus is useful forcovering any cylindrical object with stocking material which can takethe form of covers, coils, piles, etc.

The operation of the above machinery line is summarized in the followingcycle. Tube stock 30 is fed into the combination saw-transfer table androlls under the force of gravity down the inclined table 76 to thefeeder indexing fingers 78. Upon a signal from the photocell 96 that thebelt conveyor is free of tubes 22, both the feeder indexing fingers 78and the discharge indexer 90 are rotated ninety degrees, therebydepositing tube stock 30 within the awaiting carrier hooks 82 anddropping previously cut pieces retained by the discharge indexer 90 ontothe belt conveyor 34. The carrier hooks are rotated to pass the tubestock 30 through the saw blades 86 where the tube stock 30 is cut intosized tubes 22 and deposited on the inclined table 76 to roll undergravitational force to the discharge indexer 90. A limit switchactivated by a cam (neither illustrated) on drum 84 retaining thecarrier hooks 82 stops the rotation of the drum 84 indexing fingers 78and discharge indexer 90. The tubes deposited on the belt conveyor 34are transferred to the abutting guide track 108 and there engaged by thedrive roller 40. The drive roller 40 engages each tube 22 and pushes thetube against a preceding tube through the dust collector 44 which cleansthe outside surface of the tubes 22 and through the mandrel 46 in theoperative position on the stocking machine 42. Upon being pushed out ofthe mandrel 46, the tubes 22 engage the stocking 48, covering theoutside of the mandrel 46, on the inner wall of the stocking 48 therebycovering the tubes as they exit the mandrel. Both tubes 22 and stocking48 are then individually engaged by the separating roller 54 beingguided thereto by a continuation of the guide track 108 on the exit endof the stocking machine 42. The separating roller 54 drives the tube 22and stocking 48 thereon at a speed exceeding the rate of advance of thetubes 22 driven by the drive roller 40 as the tubes 22 exit the mandrel46. The difference in the speeds of the tubes 22 approaching and leavingthe separating wheel 54 causes a separation between the tubes 22 withinthe stocking material 48. This separation is maintained by the tractionroller 58 which turns at the same speed as the separating roller 54. Thetraction roller maintains tension on the stocking 48 between the rollers54 and 58 to assure a clean cut of the flying shear 56 which passesthrough the stocking 48 when the separation between the tubes 22 withinthe stocking 48 is approximately centered on the shear 56. The shear 56in making a forward pass severs the stocking 48 into stocking covers 24which have ends overhanging the tubes 22. The shear 56 cuts anothercover 24 upon the return pass by virtue of its double edge. The tube 22and stocking cover 24 assemblies upon leaving the traction wheel arepushed piece against piece to the end of the guide track 108 where itabutts with the lateral transfer platform 62. As the pieces are advancedonto the transfer platform 62, they contact a limit switch 188 which inturn activates a plunger 190 which pushes them laterally off the bed 176of the platform to fall by gravity down the inclined plate 184 into theflight 186 of the flight conveyor 64. The flight conveyor 64 is advancedtwo flights 186 for each forward and return pass of the flying shear 56and advances the tube 22 and stocking cover 24 assemblies laterallytoward the nozzle-ram machine 68. A sufficient length of conveyor 64 isprovided between transfer platform 62 and nozzle-ram machine 68 to allowan attendant to insert both of the ends of the stocking covers 24 and toposition and align tube cores 26 into both ends of the tubes 22. Theattendant only positions and aligns the cores 26 within the tubes 22 forinsertion by the rams 70. The rams 70 and nozzles 72 of the nozzle-rammachine 68 complete the cycle by the rams 70 converging on two tubes 22at a time to push the extended cores 26 into the tubes 22 forming afilter unit 28, and by the nozzles 78 likewise converging on two filterunits 28 at a time to blow out residual loose material from within theunits 28 with high velocity air. To accommodate two pieces at a time,the nozzle-ram machine 68 is activated only upon the shear 56 returningto its starting position, having made two passes and indexed the flightconveyor 64 twice.

The present machinery line incorporates previously manually accomplishedoperations into a line process which approaches complete automation. Themachinery line is a time saver due to its increased speed over themanual operations. The continuous nature of the process of the linemakes the line more efficient. The higher speed and greater efficiencyof continuous operations over individual manual operations results in ahigher production of filter units 28. Further, the machine can performthe same operations absent the presence of an attendant at eachoperation, thereby requiring less working space due to the resultingcompactness.

While the method of covering cylindrical articles has been describedabove in relation to the operation of the machinery line, it should beunderstood that the method could be practiced not only by otherapparatus, but manually as well. Thus, cylindrical articles could beinserted into one end of a cylinder having its other end and outersurface covered with a continuous length of covering material. As asufficient number of articles were inserted into the cylinder, the firstarticle inserted and subsequent abutting articles would be forced toemerge from the covered end of the cylinder. The emerging article couldthen be grasped, while within the covering material, and both articleand that portion of the covering material now upon the article could bepulled away from the cylinder. When the article had sufficiently clearedthe cylinder, separation from the previously abutting article would alsohave occurred to allow the covering material to be sheared between thisfirst article and the following article. Since the emerging articleengages the inner wall of the overhanging covering material and carriesthe covering material along with it, both ends of the article now havecovering material overhanging them. The overhanging material could betucked into the hollow ends of the article and these ends could beretained by subsequently inserted tubular cores which force the ends ofthe covering material against the inner wall of the articles. Thisprocedure can be repeated indefinitely as additional articles areinserted into the open end of the cylinder.

In accordance with the provisions of the patent statutes, the principleand mode of operation of the apparatus and the method of fabrication ofsheathed cylinders have been explained and what is considered torepresent their best embodiments have been illustrated and described. Itshould, however, be understood that the invention may be practicedotherwise than as specifically illustrated and described withoutdeparting from its spirit or scope.

We claim:

1. Apparatus for producing covered articles, comprising:

means for directing a plurality of discrete lengths of articles along apath:

means for applying a continuous length of covering material to the outerperipheral surface of said plurality of articles as the latter movealong a predetermined portion of said path; means for at leastmomentarily changing the relative speed between those articles withinsaid covering material and those articles not within said coveringmaterial whereby the adjacent ends of said articles within said coveringmaterial are separated; and

means for severing said covering material intermediate the adjacent endsof said articles after said adjacent ends have been separated.

2. Apparatus defined in claim 1 wherein said directing means includes aguide track for guiding said articles.

3. Apparatus defined in claim 2 wherein said directing means furtherincludes drive means for positively driving said articles in said guidetrack.

4. Apparatus defined in claim 3 wherein said drive means includes adriven roller having a peripheral surface for drivingly engaging saidarticle.

5. Apparatus defined in claim 1 wherein sad means for applying thecovering material includes a hollow open ended conduit encompassed bysaid covering material, said conduit being of sufficient cross sectionaldimension to permit the passage of said articles therethrough.

6. Apparatus defined in claim 5 wherein said means for applying thecovering includes means for moving said hollow conduit into and out ofalignment with said directing means.

7. Apparatus defined in claim 6 wherein said means for applying thecovering material includes a second hollow open ended conduit mounted onsaid moving means for alternate selective alignment with said directingmeans.

8. Apparatus defined in claim 1 wherein said separating means includes adriven roller for imparting movement to said articles within thecovering material at a speed greater than the speed imparted thereto bysaid directing means to effect a separation of said articles within saidcovering material.

9. Apparatus defined in claim 1 wherein said severing means comprises apair of knife blades and means to drive said blades with synchronizedopposed motion whereby the cutting edges pass each other as they passthrough the stocking.

10. Apparatus defined in claim 9 wherein said severing means includesmeans for moving said blade transversely with respect to the movement ofsaid articles within said covering material.

11. Apparatus defined in claim 10 including driven roller means formaintaining separation of said articles within the covering material.

12. Apparatus defined in claim 1 wherein said articles are hollow andopen ended cylinders.

13. Apparatus as defined in claim 12 including means for insertingtubular cores within the interior of said covered articles.

14. Apparatus defined in claim 13 wherein said inserting means includesa pair of opposing and converging rams located adjacent the ends of saidarticles.

15. Apparatus defined in claim 13 including means for applying pressurefluid to the interior of said articles subsequent to the insertion ofsaid tubular cores.

16. Apparatus defined in claim 15 wherein said means for applying fluidpressure includes a nozzle adapted to seat on the end of said article.

17. Apparatus defined in claim 16 including a second nozzle opposingsaid first nozzle for receiving the pressurized fluid emitted by saidfirst nozzle subsequent to the passage thereof through the interior ofsaid hollow covered articles.

18. Apparatus defined in claim 17 wherein said first and second nozzlesare movable toward and away from one another.

19. Apparatus for producing covered cylindrical articles comprising:

a hollow cylindrical housing having an inlet and an outlet;

a source of discrete lengths of cylindrical articles;

a first driven roller means engaging the outer surface of saidcylindrical articles for imparting movement thereto through saidcylindrical housing from the inlet to the outlet thereof;

a source of covering material for said cylindrical articles surroundingsaid cylindrical housing;

a second driven roller means disposed at the outlet of said cylindricalhousing engaging said covering and said cylindrical articles as saidarticles emerge from the outlet of said housing to impart movementthereto at a speed greater than the speed imparted by said first drivenroller means to effect a separation between adjacent ends of saidarticles within said covering material;

a third driven roller means imparting movement to said articles withinsaid covering material at a speed equal to the speed imparted by saidsecond driven roller means to maintain separation of said articleswithin said covering material; and

means for severing said covering material in the region between theseparated ones of said articles.

20. The method of covering articles, comprising:

directing a plurality of discrete lengths of articles along a path;

applying a continuous length of covering material to the outerperipheral surface of said plurality of articles;

at least momentarily changing the relative speed between those articleswithin said covering and those articles not within said covering so thatsaid articles within said covering material are separated; and

severing said covering material intermediate the adjacent ends of saidseparated articles. 21. The method according to claim wherein saidarticles are hollow and open ended and including the following steps:

tucking the ends of said covering material into the open ends of saidhollow open ended articles; and

inserting tubular cores into at least one end of said open endedarticles to engage said covering material ends between the inside ofsaid open ended articles and said cores.

22. The method according to claim 21 including the step of cleaning theoutside of said articles before covering said articles.

23. The method according to claim 21 including the step of applyingfluid pressure to the interior of said hollow open ended articles.

24. The method of assembling filter units, comprismg:

cutting tubular stock of fiber glass material into discrete lengths;

cleaning the outside of said tubes;

directing a plurality of discrete lengths of said tubes to the interiorof an extended length of an outer covering;

at least momentarily changing the relative speed between those articleswithin said covering and these articles not with said covering so thatsaid tubes within said covering material are separated;

severing said covering material intermediate the adjacent ends of saidseparated tubes;

tucking the ends of said covering material into the open ends of saidtube;

inserting perforated metallic tube cores into each end of said tube toengage the end of said covering material between the inside of said tubeand the outside of said cores; and

applying a pressurized fluid to the interior of said covered tubes.

1. Apparatus for producing covered articles, comprising: means fordirecting a plurality of discrete lengths of articles along a path:means for applying a continuous length of covering material to the outerperipheral surface of said plurality of articles as the latter movealong a predetermined portion of said path; means for at leastmomentarily changing the relative speed between those articles withinsaid covering material and those articles not within said coveringmaterial whereby the adjacent ends of said articles within said coveringmaterial are separated; and means for severing said covering materialintermediate the adjacent ends of said articles after said adjacent endshave been separated.
 2. Apparatus defined in claim 1 wherein saiddirecting means includes a guide track for guiding said articles. 3.Apparatus defined in claim 2 wherein said directing means furtherincludes drive means for positively driving said articles in said guidetrack.
 4. Apparatus defined in claim 3 wherein said drive means includesa driven roller having a peripheral surface for drivingly engaging saidarticle.
 5. Apparatus defined in claim 1 wherein sad means for applyingthe covering material includes a hollow open ended conduit encompassedby said covering material, said conduit being of sufficient crosssectional dimension to permit the passage of said articles therethrough.6. Apparatus defined in claim 5 wherein said means for applying thecovering includes means for moving said hollow conduit into and out ofalignment with said directing means.
 7. Apparatus defined in claim 6wherein said means for applying the covering material includes a secondhollow open ended conduit mounted on said moving means for alternateselective alignment with said directing means.
 8. Apparatus defined inclaim 1 wherein said separating means Includes a driven roller forimparting movement to said articles within the covering material at aspeed greater than the speed imparted thereto by said directing means toeffect a separation of said articles within said covering material. 9.Apparatus defined in claim 1 wherein said severing means comprises apair of knife blades and means to drive said blades with synchronizedopposed motion whereby the cutting edges pass each other as they passthrough the stocking.
 10. Apparatus defined in claim 9 wherein saidsevering means includes means for moving said blade transversely withrespect to the movement of said articles within said covering material.11. Apparatus defined in claim 10 including driven roller means formaintaining separation of said articles within the covering material.12. Apparatus defined in claim 1 wherein said articles are hollow andopen ended cylinders.
 13. Apparatus as defined in claim 12 includingmeans for inserting tubular cores within the interior of said coveredarticles.
 14. Apparatus defined in claim 13 wherein said inserting meansincludes a pair of opposing and converging rams located adjacent theends of said articles.
 15. Apparatus defined in claim 13 including meansfor applying pressure fluid to the interior of said articles subsequentto the insertion of said tubular cores.
 16. Apparatus defined in claim15 wherein said means for applying fluid pressure includes a nozzleadapted to seat on the end of said article.
 17. Apparatus defined inclaim 16 including a second nozzle opposing said first nozzle forreceiving the pressurized fluid emitted by said first nozzle subsequentto the passage thereof through the interior of said hollow coveredarticles.
 18. Apparatus defined in claim 17 wherein said first andsecond nozzles are movable toward and away from one another. 19.Apparatus for producing covered cylindrical articles comprising: ahollow cylindrical housing having an inlet and an outlet; a source ofdiscrete lengths of cylindrical articles; a first driven roller meansengaging the outer surface of said cylindrical articles for impartingmovement thereto through said cylindrical housing from the inlet to theoutlet thereof; a source of covering material for said cylindricalarticles surrounding said cylindrical housing; a second driven rollermeans disposed at the outlet of said cylindrical housing engaging saidcovering and said cylindrical articles as said articles emerge from theoutlet of said housing to impart movement thereto at a speed greaterthan the speed imparted by said first driven roller means to effect aseparation between adjacent ends of said articles within said coveringmaterial; a third driven roller means imparting movement to saidarticles within said covering material at a speed equal to the speedimparted by said second driven roller means to maintain separation ofsaid articles within said covering material; and means for severing saidcovering material in the region between the separated ones of saidarticles.
 20. The method of covering articles, comprising: directing aplurality of discrete lengths of articles along a path; applying acontinuous length of covering material to the outer peripheral surfaceof said plurality of articles; at least momentarily changing therelative speed between those articles within said covering and thosearticles not within said covering so that said articles within saidcovering material are separated; and severing said covering materialintermediate the adjacent ends of said separated articles.
 21. Themethod according to claim 20 wherein said articles are hollow and openended and including the following steps: tucking the ends of saidcovering material into the open ends of said hollow open ended articles;and inserting tubular cores into at least one end of said open endedarticles to engage said covering material ends between the inside ofsaid open ended articles and said cores.
 22. The method according toclaim 21 including the step of cleaning the outside of said articlesbefore covering said articles.
 23. The method according to claim 21including the step of applying fluid pressure to the interior of saidhollow open ended articles.
 24. The method of assembling filter units,comprising: cutting tubular stock of fiber glass material into discretelengths; cleaning the outside of said tubes; directing a plurality ofdiscrete lengths of said tubes to the interior of an extended length ofan outer covering; at least momentarily changing the relative speedbetween those articles within said covering and these articles not withsaid covering so that said tubes within said covering material areseparated; severing said covering material intermediate the adjacentends of said separated tubes; tucking the ends of said covering materialinto the open ends of said tube; inserting perforated metallic tubecores into each end of said tube to engage the end of said coveringmaterial between the inside of said tube and the outside of said cores;and applying a pressurized fluid to the interior of said covered tubes.